Battery tab and packaging frame design

ABSTRACT

Improved battery packaging and constructions for batteries, particularly thin, flat-profile packaged batteries are provided. The battery packaging constructions may eliminate the need for soldering by providing current collector tabs coated by electrically conductive adhesive tape such as z-axis conductive tape and may provide support for current collector tabs and a regular battery perimeter by providing supportive battery packaging and/or frame materials. Better fabrication results, particularly when the batteries are used in smart cards, RFID tags, and medical devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/466,900, filed May 15, 2009, pending, which is a divisional of U.S.patent application Ser. No. 11/187,440, filed on Jul. 22, 2005,abandoned, which claims the benefit of U.S. provisional patentapplication No. 60/589,845, filed Jul. 22, 2004. Each of theabove-referenced applications is incorporated herein by reference in itsentirety.

BACKGROUND

Thin package batteries such as polymer electrolyte batteries and lithiumbatteries are popular for use in many applications due to their lowbattery weight, long service life and high power densities. Thesebatteries are typically fabricated with anode and cathode currentcollector tabs associated with the anode and cathode respectively todraw electric energy from the battery cell to an external load. Becauseit is desirable to minimize the size and weight of these batteries,however, the current collector tabs are generally designed to be flimsytabs extending outwardly from the battery cell and through to theexterior of any battery packaging. As a result, the anode and cathodecurrent collector tabs are generally susceptible to breaking off ortearing and are easily damaged during processing and installation. Inaddition, because the current collector tabs protrude beyond the anodeand the cathode, they create an irregular perimeter around the batterycell. Upon lamination of the cell in a thin device, such as a smart cardor smart label, a sink or pocket may be created by the space between theprotruding tabs, resulting in surface defects that negatively affect theappearance of the device. Another significant drawback of conventionalthin packaged battery designs is that the protruding current collectortabs typically require a soldering or welding step in order to make anelectrical connection between the tabs and the electrical circuitry ofthe device into which they are to installed. Depending upon the geometryof the device in which the batteries are installed, this soldering orwelding step may be difficult or impractical.

Thus, a need exists for a thin packaged battery that may be installedeasily in a variety of devices without the risk of damaging the currentcollector tabs or creating sink holes or pockets in the device uponlamination.

SUMMARY

Batteries having improved constructions and packagings are provided. Thebatteries are designed to provide at least one of the followingadvantages: 1) some of the batteries provided herein do not require asoldering or welding step in order to be connected to an externalelectronic device; 2) some of the batteries provided herein includereinforced current collector tabs; and 3) some of the batteries providedherein have regular perimeter shape, such as a square or rectangularshape, which helps eliminate surface defects when the batteries areincorporated into small and/or flat electric devices such as smart cardsor smart labels. The battery constructions provided herein arewell-suited for the design of thin, flat-profile batteries, includinglaminate battery structures.

The batteries generally include a cell comprising an anode, a cathodeand an electrolyte sandwiched between the anode and the cathode. Ananode current collector tab can extend outwardly beyond the edge of theanode, and a cathode current collector tab can extend outwardly beyondthe edge of the cathode.

In a first embodiment, the invention provides a battery comprising: (a)a battery cell, (b) at least one current collector tab extendingoutwardly from the battery cell, and (c) electrically conductiveadhesive tape disposed on the current collector tab extending from thebattery cell. In some embodiments, the batteries include two currentcollector tabs extending outwardly from the battery cell andelectrically conductive adhesive tape disposed on one or both of thecurrent collector tabs which allow the tabs to be electrically connectedto an external electronic device without soldering or welding the tabsin place. In some battery designs a separate piece of electricallyconductive adhesive tape is placed on each current collector tab. Inthese embodiments the tape may be isotropically conductive. In otherbattery designs a strip of z-axis anisotropically electricallyconductive adhesive tape (i.e., tape that conducts only in the directionperpendicular to the plane of the tape) is placed over and bridging bothcurrent collector tabs. In this design the strip of tape partially orentirely covers the space defined between the two tabs and creates amore regular perimeter for the battery.

In some embodiments the batteries include a frame disposed around theperiphery of the battery cell. A portion of this frame can be disposedadjacent and in contact with at least one current collector tab.

In another embodiment, the invention provides a battery with a doubleframe design, the battery comprising: (a) a battery cell; (b) at leastone current collector tab having a distal end extending from the batterycell; (c) a tab support frame disposed around the periphery of thebattery cell; and (d) an opposing frame disposed opposite andsubstantially parallel to the tab support frame; wherein the at leastone current collector tab is disposed between the tab support frame andthe opposing frame and further wherein a portion of the at least onecurrent collector tab extends beyond the edge of the opposing frame butnot beyond the edge of the tab support frame.

In this battery design, the support frame material serves as a supportfor the current collector tab and provides a more regular perimeter forthe battery. However, the current collector tab remains exposed andaccessible to electrical contact from the direction opposite the supportframe. As a result electrically conductive adhesive tape may be appliedover the exposed surface of the current collector tab in order toprovide electrical connections between the tab and electrical contactsin a device into which the battery is to be installed.

In still another embodiment, the invention provides a battery with asingle frame design, the battery comprising: (a) a battery cell; (b) atleast one current collector tab having a distal end extending from thebattery cell; (c) a tab support frame disposed below the batter cell andhaving an outer edge that extends beyond the periphery of the batterycell; and (d) a lower packaging material disposed below the batterycell; wherein the at least one current collector tab is supported by thetab support frame. Typically, the battery will also include an upperpackaging material disposed above the battery cell. Together, the upperand lower packaging materials may form a pouch for the battery cell. Insome embodiments, the upper packaging material has an outer edge thatdoes not extend to the distal end of the current collector tab, suchthat a portion of the current collector tab extends beyond the outeredge of the upper packaging material but not beyond the outer edge ofthe tab support frame.

As in the previous embodiment, the support frame material serves as asupport for the current collector tab and provides a more regularperimeter for the battery. However, the current collector tab remainsexposed and accessible to electrical contact from the direction oppositethe support frame. Electrically conductive adhesive tape may be appliedover the exposed surface of the current collector tab.

In yet another embodiment, the invention provides a battery with aframeless design, the battery comprising: (a) a battery cell; (b) atleast one current collector tab having a distal end extending from thebattery cell; (c) a lower packaging material disposed below the batterycell and having an outer edge that beyond the periphery of the batterycell; wherein the lower packaging material supports the currentcollector tab. Typically, the battery will also include an upperpackaging material disposed above the battery cell. Together, the upperand lower packaging materials may form a pouch for the battery cell. Insome embodiments, the upper packaging material has an outer edge thatdoes not extend to the distal end of the current collector tab, suchthat a portion of the current collector tab extends beyond the outeredge of the upper packaging material but not beyond the outer edge ofthe lower packaging material. It should be understood that the “lowerpackaging material” and an “upper packaging material” may be composed ofseparate pieces of packaging material or of a single continuous piece ofpackaging material that is, for example, folded over a battery cell. Inthe latter case the terms “upper packaging material” and the “lowerpackaging material” simply refer to different section of the continuouspiece of packaging material.

In this design, the lower packaging material serves as a support for thecurrent collector tab and provides a more regular perimeter for thebattery. However, the current collector tab remains exposed andaccessible to electrical contact from the direction opposite the lowerpackaging material. Electrically conductive adhesive tape may be appliedover the exposed surface of the current collector tab. In someinstances, this design may result in a packaged battery having anon-uniform cross-sectional height, wherein the cross-sectional heightof the packaged battery is larger in the center (where the battery cellis located) that at the ends (e.g., where the packaging materials and/orconductive tape come together). In such instances, the battery mayinclude an external frame designed to seats around the raised center ofthe packaged battery (i.e., around the battery cell) to provide a moreuniform cross-sectional height.

In another embodiment, the invention provides a method of forming anelectrical connection between a battery comprising at least one currentcollector tab and a battery-powered device, the method comprisingdisposing electrically conductive adhesive tape between the currentcollector tab and an electrical contact of the battery-powered device.

In another embodiment, the invention provides a method for forming abattery having at least one current collector tab, the method comprisingapplying electrically conductive tape to the current collector tab.

In another embodiment, the invention provides a method for forming abattery comprising a battery cell with at least one current collectortab extending outwardly therefrom, the method comprising:

(a) providing a tab support frame disposed around the periphery of thebattery cell;

(b) providing an opposing frame disposed opposite and substantiallyparallel to the tab support frame; and

(c) disposing at least one current collector tab between the tab supportframe and the opposing frame such that a portion of the currentcollector tab extends beyond the edge of the opposing frame but notbeyond the edge of the tab support frame.

In another embodiment, the invention provides a method for forming abattery comprising a battery cell with at least one current collectortab extending outwardly therefrom, the method comprising:

(a) providing a tab support frame disposed around the periphery of thebattery cell;

(b) providing an upper packaging material disposed above and extendingbeyond the periphery of the battery cell;

(c) disposing at least one current collector tab between the tab supportframe and the upper packaging material such that a portion of thecurrent collector tab extends beyond the edge of the upper packagingmaterial but not beyond the edge of the tab support frame; andoptionally;

(d) disposing a lower packaging support frame disposed below the tabsupport frame.

In another embodiment, the invention provides a method for forming abattery comprising a battery cell with at least one current collectortab extending outwardly therefrom, the method comprising:

(a) providing a lower packaging material disposed below and extendingbeyond the periphery of the battery cell;

(b) providing an upper packaging material disposed above and extendingbeyond the periphery of the battery cell;

(c) disposing at least one current collector tab between the lowerpackaging material and the upper packaging material such that a portionof the current collector tab extends beyond the edge of the upperpackaging material but not beyond the edge of the lower packagingmaterial; and optionally;

(d) an external frame disposed above the upper packaging material orbelow the lower packaging material and seated around the periphery ofthe battery cell.

In other embodiments, the invention provides use of z-axis conductivetape to provide electrical connection between a battery tab and anexternal device. Also provided is a packaged lithium battery comprisingtwo tabs extending from the battery cell, wherein the tabs are incontact with z-axis conductive tape, and a frame member or a packagingmaterial which is substantially flush with the distal ends of the tabs.In an alternative embodiment, the outer edge of the (lower) packagingmaterial or frame member is not substantially flush with the distal endof the at least one current collector, and the distal end of the currentcollector extends beyond the outer edge of the (lower) packagingmaterial or frame member.

The batteries may be used in a broad range of devices. However they areparticularly well suited for use inside smart cards, smart labels, RFIDtags, medical devices, and other small devices which require hightemperature/high pressure lamination processing and which benefit froman on board power supply. Although batteries are a preferred embodiment,other embodiments of the invention are with other types ofelectrochemical systems such as, for example, supercapacitors andmembrane-electrode assemblies.

A basic and novel feature of some of the embodiments is that batterystructures can be made without the need to solder or weld currentcollector tabs. Another basic and novel feature is the use of conductiveadhesives, including curable conductive adhesives, to provide electricalconnections between current collector tabs and external devices. Thesefeatures represent important manufacturing improvements.

DRAWINGS

FIG. 1 shows the components of a battery having a double frame design inan embodiment of the present invention in a exploded, disassembledstate.

FIGS. 2A and 2B show the components of a battery having a double framedesign in an embodiment of the present invention in an assembled state.

FIG. 3 shows an expanded view of a multilayered outer packagingmaterial.

FIG. 4 shows an expanded view of a multilayered frame material.

FIG. 5 shows an illustrative assembly process for producing a batterycell having an anode, a cathode, an electrolyte, and an anode currentcollector tab.

FIG. 6 shows an assembly process for packaging multiple battery cellsproduced by the assembly process of FIG. 5.

FIG. 7 illustrates an exploded view of an embodiment which uses a singlepiece frame to support current collector tabs.

FIG. 8 illustrates an exploded view of an embodiment which uses no framebut uses the packaging material to support current collector tabs.

FIGS. 9A (top) and 9B (bottom) illustrate perspective views of thebattery of FIG. 8 in an assembled state.

FIGS. 10A (top) and 10B (bottom) illustrate an external frame embodimentto provide greater uniformity in thickness, wherein FIG. 10A shows anexploded view and FIG. 10B shows a perspective, assembled view.

DETAILED DESCRIPTION

Batteries having improved packaging and construction and methods for theproduction of those batteries are provided. In some embodiments, thebatteries provided herein do not require a soldering or welding step inorder to be connected to an external electronic device. In otherembodiments, batteries with reinforced current collector tabs areprovided. In still other embodiments, batteries having a regularperimeter shape, such as a square or rectangular shape, are provided.Finally, some of the batteries provided herein include a combination oftwo or more of these features.

The batteries include a battery cell having an anode, a cathode, and anelectrolyte disposed between the anode and the cathode. An anode currentcollector tab for delivering electric energy from the battery cell to anexternal device is attached to and extends outwardly beyond theperiphery of the anode. Similarly, a cathode current collector tab isattached to and extends outwardly beyond the periphery of the cathode.The battery designs provided herein may be used with a broad range ofbatteries including, but not limited to, metal hydride (e.g., Ni-MH)batteries, nickel-cadmium (Ni—Cd) batteries, lithium ion, and lithiummetal batteries. These batteries may have solid, liquid or polymerelectrolytes. Examples of batteries that are suitable for use in thepresent invention are described in U.S. patent application Ser. Nos.10/437,778; 10/437,559; and 10/437,546, filed May 13, 2003 to Wensley etal., the entire disclosures of which are incorporated herein byreference. Other suitable batteries are described in U.S. ProvisionalPatent Application No. 60/545,179, filed Feb. 18, 2004 (see also, Ser.No. 11/061,751 filed Feb. 18, 2005), the entire disclosure of which isincorporated herein by reference. Other batteries and battery elementsare described in, for example, U.S. Pat. Nos. 5,888,672 and 6,451,480 toGustafson et al. which are hereby incorporated by reference in theirentirety.

Other battery elements, designs, and packagings are known in the art andcan be adapted to be used with the present invention, includingtechnology described in, for example, U.S. Patent application no.2003/0059673 to Langan et al., and U.S. Pat. No. 6,080,508 to Dasguptaet al.; U.S. Pat. No. 6,251,537 to Kim et al.; U.S. Pat. No. 6,515,449to Thomas et al.; U.S. Pat. No. 5,965,298 to Harada et al.; U.S. Pat.No. 6,610,445 to Moriwaki et al.; U.S. Pat. No. 6,656,232 to Usui etal.; U.S. Pat. No. 5,057,385 to Hope et al.; U.S. Pat. No. 5,326,653 toChang; U.S. Pat. No. 5,456,813 to Grange-Cossou et al.; U.S. Pat. No.6,045,946 to Maggert et al.; U.S. Pat. No. 6,106,975 to Watanabe et al.;U.S. Pat. No. 6,145,280 to Daroux et al.; and U.S. Pat. No. 6,267,790 toDaroux et al.

The invention encompasses a variety of battery shapes includingrectilinear or curvilinear structures. Preferred shapes include squareand rectangular. The shape can be curved or rounded. The shape of thebattery is preferably adapted to fit cleanly into a larger structuresuch as the pocket of a smart card. In many cases, the shape is keptsimple such as a rectangle or circle to facilitate inexpensivemanufacturing and strong structures.

The anode current collector tab and the cathode current collector tabare desirably made from a conductive web or sheet like material. In someembodiments of the batteries, the current collector tabs are composed ofmetal foils such as aluminum, copper, or nickel foils. Tabs based onelectrodeposited copper or nickel flashed copper can be used. Thecurrent collector tab can be, for example, an electrodeposited coppertab (18 microns). The current collector tabs are desirably thin so thatpackaging materials may be easily sealed around them. For example, thecurrent collector tabs may have a thickness of no more than about 10mils and desirably, no more than about 1 mil (where 1 mil= 1/1000 inch).However, current collector tabs having a thickness outside of theseranges may also be employed. In some embodiments, the current collectortabs may comprise an extension protruding from a larger currentcollector sheet disposed adjacent an anode or a cathode. In otherembodiments, the tab may comprise a strip of material disposed on, andextending outwardly beyond the edge of, a current collector sheet, ananode or a cathode.

One aspect of the present invention provides a battery that may beeasily installed in a variety of electronic devices without the need tosolder or weld the current collector tabs to the circuitry of thedevice. This aspect of the invention provides a battery that includes atleast one current collector tab. For example, the battery may include ananode having an anode current collector tab extending outwardly from itsperiphery, a cathode having a cathode current collector tab extendingoutwardly from its periphery, an electrolyte disposed between the anodeand the cathode, and electrically conductive adhesive tape disposed onthe anode current collector tab and/or on the cathode current collectortab. In this construction, the electrically conductive adhesive tapeforms the electrical connection between each current collector tab andone or more electrical contacts in the device into which the battery isto be installed. This electrical connection eliminates the need tosolder or weld the battery tabs in place. Further description isprovided below for FIGS. 1 and 2.

In some battery designs, a separate piece of electrically conductiveadhesive tape may be placed on each of the two current collector tabs.In this design, the electrically conductive adhesive tape may beisotropically electrically conductive or anisotropically conductive.Anisotropically conductive tapes are not electrically conductive alongall of their dimensions. For example, z-axis anisotropically conductivetape generally conducts electricity along its z-axis (i.e., in thedirection perpendicular to the plane of the tape). In an alternativebattery design, a strip of the electrically conductive adhesive tape isplaced over both current collector tabs such that it bridges the tabs.In order to maintain electrical isolation between the two currentcollector tabs, anisotropically conductive tape which conducts generallyalong the z axis is used in this design. The use of a strip ofelectrically conductive adhesive tape across both tabs may beadvantageous because the tape helps to fill the space between the tabs,making the perimeter of the battery cell more regular and helping toprevent sink holes or other surface defects from forming when thebattery is laminated into a thin device, such as a smart card or label.

The electrically conductive adhesive tapes used to make the electricalcontacts are typically made from adhesives having electricallyconductive particles dispersed therein. The electrically conductivetapes optionally include a release liner which may be easily removed toexpose the adhesive tape before or after, but usually before, thebattery has been placed into a device. A variety of adhesives may beused to make the electrically conductive tapes. These include, but arenot limited to, pressure sensitive adhesives, heat sensitive adhesives,and heat curable adhesives. Specific types of adhesives that may be usedto construct the electrically conductive adhesive tapes include, but arenot limited to, acrylic adhesives, silicone adhesives, epoxy adhesives,and polyether amide adhesives. Electrically conductive fibers andparticles, which generally can have anisotropic shape to provideanisotropic properties, may be dispersed in the adhesives include, butare not limited to, nickel particles, gold coated polymer particles, andsilver coated glass particles. Suitable electrically conductive adhesivetapes are commercially available from 3M. Specific examples ofanisotropically electrically conductive tapes available from 3M includeElectrically Conductive Tape 9703, Z-Axis Adhesive Film 5460R, Z-AxisAdhesive Film 5552R, Z-Axis Adhesive Film 7313, and Z-Axis Adhesive Film7303. Another suitable example of an anisotropically conductive (z-axis)tape that may be used in the production of the present batteries isdescribed by Ishibashi et al., AMP Journal of Technology, 5, 24-30(1996).

Technical literature further describing tapes, anisotropic tapes, andanisotropic conductive tapes include, for example, U.S. Pat. No.6,260,262 (3M); U.S. Pat. Nos. 5,422,200; 6,517,618; 6,293,470 andpatent publications 2003/0002132; 2003/0209792; and 2001/0015483.

A second aspect of the present invention provides a battery having oneor more supported current collector tabs. In one embodiment of thisaspect of the invention, the battery cell includes a frame around itsperiphery. The peripheral frame may be a two-piece frame with a firstframe around the anode or generally associated with the anode side, anda second frame around the cathode or generally associated with thecathode side. At least one current collector tab can extend outwardlyfrom the edge of the battery between the two frames. One end of oneframe (i.e., the “tab support frame”) is longer than the correspondingend of the other frame (i.e., the “opposing frame”) such that the tabsupport frame provides support for the current collector tab on oneside, while leaving the tab exposed and accessible from the opposingside. As previously described, the exposed side of the tab may have anelectrically conductive adhesive tape disposed thereon in order toprovide electrical contact between the current collector tab and theelectronic device into which the battery is to be installed. In someembodiments the peripheral frame may be in the form of a pocket orsleeve in which the two frames are actually sealed together at one ormore points or along one or more edges, such that the battery cell canbe slipped into the peripheral frame. In some embodiments, the tabsupporting end of the tab support frame is long enough that the leadingedge of the support frame is flush with or extends beyond the distal endof the current collector tab such that the tab support frame provides aregular battery perimeter. In some embodiments, the frame actually has acentral opening into which a battery cell may be inserted. In otherembodiments the frame may be a continuous sheet of material that coversand extends beyond the periphery of a battery cell, such that theperipheral edges of the sheet “frame” the battery. Further descriptionis provided below with respect to the figures.

Conventional battery frame materials can be used including thermoplasticplastics. The frame material is typically a plastic, such aspolyethylene terephthalate (PET), desirably having a total thicknessthat is substantially the same as the thickness of the battery cellitself, whether the frame is one piece or comprises two or more pieces.In some embodiments, the frame can comprise a PET layer (200 microns)sandwiched between layers of MR PVA (24 and 9 micron layers). Each frameis characterized by an interior surface which is the surface facingtowards the current collector tabs and an exterior surface which is theopposing surface facing away from the current collector tabs. The framematerial may be a multilayered material including a polymeric layer andone or more sealant layers adapted to seal the frames to one another, tothe tabs and/or to an outer packaging layer. For example, a tab sealantmay optionally be applied to at least a portion of the interior surfaceof the tab support frame in order to adhere the current collector tabsto that frame. Alternatively, the tab sealant may be applied to thecurrent collector tabs before they are contacted with the tab supportframe. This tab sealant is desirably a material that not only heat sealsto itself, but also bonds strongly to the current collector tabs of thebattery and preferably activates between about 90° C. and 100° C. Insome embodiments, the sealant may be a low temperature pressureactivated sealant.

The battery cells typically include an electrically insulative anddesirably moisture and vapor resistant packaging material surroundingthe battery cell. The packaging material may be a multilayered packagingmaterial including one or more sealing layers, one or more electricallyinsulative layers and one or more moisture and/or vapor barrier layers.For example, the outer packaging material may have a binder adhesivecoated on at least a portion of its exterior surface to help bind thebattery into an electronic device, such as a smart card. The binderadhesive is desirably a heat activated adhesive which activates attemperatures of at least about 100.degree. C. A binder adhesive may alsobe applied to at least a portion of the interior surface of thepackaging material to bind the outer packaging material to the batterycell and/or frames. This interior binder adhesive desirably has anactivation temperature which is lower than the activation temperature ofthe exterior binder adhesive. In one embodiment, the outer packagingmaterial includes (i) an upper packaging layer disposed above andattached to the exterior surface of one of either the tab support frameor the opposing frame, and (ii) a lower packaging layer disposed belowand attached to the exterior surface of the other of the tab supportframe or the opposing frame.

Suitable materials that may be used for the various components of thebatteries, including packaging materials, anode and cathode materials,polymer electrolyte materials, and current collector and/or currentcollector tab materials, are described above including, for example, inU.S. Pat. Nos. 5,057,385; 5,326,653; and 6,145,280, the entiredisclosures of which are incorporated herein by reference, and theco-pending Wensley patent applications.

A first embodiment, therefore, is a battery comprising: (a) a batterycell, (b) at least one current collector tab extending from the batterycell, and (c) electrically conductive adhesive tape disposed on the atleast one current collector tab extending from the battery cell. In apreferred embodiment, the battery cell comprises at least two currentcollector tabs extending from the battery cell. In a preferredembodiment, the battery cell is substantially planar and substantiallyrectangular, and the current collector tab extending from the batterycell is substantially planar and substantially rectangular. In apreferred embodiment, the battery comprises a battery cell comprising:(a) an anode, (b) a cathode, (c) an electrolyte disposed between theanode and the cathode; and at least two current collector tabs extendingfrom the battery cell, wherein a first current collector tab is an anodecurrent collector tab extending from the anode, and a second currentcollector tab is a cathode current collector tab extending from thecathode. In a preferred embodiment, the cell is a substantiallyrectangular, substantially planar cell with two length sides and twowidth sides and the cell comprises at least two current collector tabsextending from one width side of the cell. In a preferred embodiment,the cell is a substantially rectangular, substantially planar cell withtwo length sides and two width sides and the cell comprises at least twocurrent collector tabs extending from one length side of the cell. In apreferred embodiment, the electrically conductive adhesive tape issubstantially planar and substantially rectangular in shape. In apreferred embodiment, the electrically conductive adhesive tape is ananisotropic electrically conductive tape that conducts in the directionperpendicular to the plane of the tape. In a preferred embodiment, theelectrically conductive adhesive tape has a length which issubstantially the same as the width of the cell. In a preferredembodiment, the current collector tab extends from the cell by a tabextension length, and the electrically conductive adhesive tape has awidth which is substantially the same as the tab extension length. In apreferred embodiment, the cell comprises at least two current collectortabs which each extend from the cell by a tab extension length which isthe same length for each of the current collector tabs, and theelectrically conductive adhesive tape has a width which is substantiallythe same as the tab extension length. The tab extension length can bemeasured by conventional means. In a preferred embodiment, the batteryhas a length with two ends and has substantially the same thickness ateach end. In a preferred embodiment, the electrically conductiveadhesive tape is an anisotropic electrically conductive tape thatconducts in the direction perpendicular to the plane of the tape,wherein the cell comprises both anode and cathode and further comprisesboth anode current collection tab and a cathode current collection tab,and the tape is disposed on both anode and cathode current collectortabs, wherein the battery is substantially shaped as a rectangle. In apreferred embodiment, the cell comprises at least two current collectortabs and separate pieces of electrically conductive adhesive tape areeach disposed on the current collector tabs without contacting eachother. In a preferred embodiment, the electrically conductive adhesivetape comprises an adhesive having conductive fibers or particlesdispersed therein. In a preferred embodiment, the electricallyconductive adhesive tape is a pressure sensitive adhesive tape. In apreferred embodiment, the electrically conductive adhesive tape is aheat sensitive adhesive tape. In a preferred embodiment, theelectrically conductive adhesive tape comprises a release liner.

In a preferred embodiment, a battery frame is disposed around theperiphery of the cell. In a preferred embodiment, a battery frame isdisposed around the periphery of the cell, and the frame comprises atleast two frame pieces including a first frame piece and a second framepiece. In a preferred embodiment, the frame comprises a polymer layerand at least one heat-sealable layer. In a preferred embodiment, abattery frame is disposed around the periphery of the cell and an outerpackaging material is disposed on the cell. In a preferred embodiment,one of the first and second frame pieces is elongated with respect tothe other so that the elongated piece can support the current collectortab or tabs. In a preferred embodiment, the leading edge of theelongated frame piece and the distal end of the tab or tabs aresubstantially flush with each other. In a preferred embodiment, thebattery comprises at least two tabs extending from the cell and thedistal end of each tab is flush with the leading edge of the elongatedframe piece.

In a preferred embodiment, the battery is a lithium metal or lithium ionbattery. In a preferred embodiment, the battery is a polymer electrolytebattery. In a preferred embodiment, the cell comprises an electrolytewith a soluble polyimide. In a preferred embodiment, the cell comprisesa polymer matrix electrolyte. In a preferred embodiment, the polymermatrix electrolyte comprises a polyimide, at least one lithium salt andat least one solvent. In a preferred embodiment, the lithium salt ispresent in a concentration of at least 0.5 moles of lithium per mole ofimide ring provided by the polyimide. In a preferred embodiment, thepolymer matrix electrolyte is substantially optically clear. In apreferred embodiment, the anode comprises a lithium powder and a polymerbinder. The polymer binder can be a high temperature polymer which isheat-resistant. For example, it can have a glass transition temperatureof at least 100° C., or at least 150° C. The polymer binder can beselected so that it does not react with the lithium powder. In oneembodiment, the polymer binder is a polyimide. In a preferredembodiment, the lithium powder has an average particle size of no morethan about 20 microns. In a preferred embodiment, the cathode comprisesa polyimide, an electronic conductive filler and a metal oxide. In apreferred embodiment, the electrolyte layer comprises solvent in anamount of about 10 wt. % to about 50 wt. %, and more particularly, about15 wt. % to about 40 wt. %, and more particularly, about 20 wt. % toabout 30 wt. %.

FIGS. 1-10 represent preferred embodiments.

FIGS. 1 and 2 show the components of an exemplary embodiment of abattery 100 in accordance with the present invention. In the designshown in these figures, a double frame construction is employed. FIG. 1shows the battery in a disassembled state while FIG. 2 shows the batteryin its assembled state. The battery includes a battery cell 102including an anode current collector tab 104 and a cathode currentcollector tab 106. The current collector tabs have distal ends 105, 107extending outwardly from the battery cell. The battery 100 furtherincludes a tab support frame 108 disposed below the battery cell 102 andan opposing frame 110 disposed above the battery cell 102. As shown inthe figure, one end 114 (i.e., the tab supporting end) of the tabsupport frame 108 has an outer edge 115 that extend out further than theouter edge 117 of corresponding end 116 of the opposing frame 110. Astrip of z-axis anisotropically electrically conductive adhesive tape118 (depicted as a transparent tape) is disposed at the end 116 of theopposing frame 110 over the anode and cathode current collector tabs104, 106. As shown in the figure, the electrically conductive tape hasan outer edge 121 that may be flush with, or substantially flush with,the distal ends 105, 107 of the current collector tabs 104, 106 and aninner edge 123 directed toward the outer edge 117 of opposing frame 110.The electrically conductive adhesive tape 118 includes a release liner120 (shown partially peeled away) that may be removed easily to exposethe electrically conductive adhesive tape 118 to electrical contacts ina device once the battery has been inserted into the device.Alternatively, the liner can be removed during the manufacture of thebattery or at any other time prior to inserting the battery into aelectrical device. As shown in the figures, the tab support frame 108provides support for the anode and cathode current collector tabs 104,106 on one side, while the electrically conductive adhesive tape 118leaves them accessible for electrical connections on the opposite side.Optionally, a tab sealant layer (e.g., an adhesive material) may beapplied to the interior surface 119 of the tab supporting end 114 of thetab support frame 108 in order to adhere the current collector tabs 104,106 to that frame. The battery may also include an outer packagingmaterial, shown here as a two part material composed of an upperpackaging layer 122 disposed above the opposing frame 110 and a lowerpackaging layer 124 disposed below the tab support frame 108. The upperand lower packaging layers 122, 124 may be attached to the opposingframe 110 and tab support frame 108 by an appropriate adhesive or heatsealing layer (not shown).

FIG. 3 shows an expanded view of a multilayered outer packaging materialthat may be used to house the battery cell 102. This material includesan insulating heat sealing layer 300 to electrically insulate thebattery cell 102 from its surroundings and to heat seal the outerpackaging material to frames 108 and 110. A vapor barrier layer 302(e.g., an aluminum layer or multilayer aluminum foils) is disposed abovethe heat sealing layer 300 and a binder layer 304 for helping to bindthe battery to an electronic device is disposed above the vapor barrierlayer 302. The outer packaging material in FIG. 3 can be used as anupper or a lower packaging material, and both the upper and lowerpackaging materials can be designed as in FIG. 3 if desired.

FIG. 4 shows an expanded view of a multilayered frame material that maybe used to frame the battery cell 102. This material includes apolymeric layer 400 sandwiched between two heat seal layers 402, 404which serve to heat seal the polymeric layer 400 around the currentcollector tabs 104, 106 and to the upper and lower packaging layers 122,124. Good bonding between an interior adhesive layer and the batterycurrent collector or frame can provide excellent flexibility.

FIG. 5 shows an illustrative assembly process for producing a bicellbattery having an anode, a cathode, an electrolyte, and an anode currentcollector. In this process, a cathode having a polymer electrolytecoated on the surface thereof 500 is provided. For adhesion purposes, asmall amount of adhesive solvent 502 may be sprayed onto the polymerelectrolyte overcoated cathode 500. After the application of thesolvent, an anode 504 such as a lithium metal anode which has an areaslightly less than the area of the polymer electrolyte overcoatedcathode 500 is placed on the polymer electrolyte overcoated cathode. Ananode current collector tab 506, which may be unwound, feed and cut froma roll of tab material 507, such as a nickel current collector material,is placed over the anode 504 such that it extends outwardly from theperiphery of the battery cell. The portion of the polymer electrolyteovercoated cathode 500 which is not covered by the anode 504, is foldedover, wrapping the polymer electrolyte overcoated cathode 500 over theanode 504 as shown in FIG. 5. The result is a thin battery bicell 508having an anode current collector tab 506 which is ready for packaging.

FIG. 6 shows an assembly process for packaging multiple battery cellsproduced by the assembly process of FIG. 5, where the steps of theassembly process shown in FIG. 5 are repeated at the top of FIG. 6 forconvenient reference. As shown in FIG. 6, a lower frame material 600 maybe rolled out from a suitable roller, the frame material being amaterial such as PET, desirably having a thickness substantially thesame as the battery cell 508 itself. Openings 604 for the battery cellsand, optionally, one or more registration holes 606, may be created inthe lower frame material 600 using a suitable window punch, aprogrammable laser cutter, or an equivalent. A cathode current collectortab 608, supplied from a suitable roller 610, is then cut, and appliedto the lower frame material 600 such that it partially overlaps a frameopening 604. Optionally, a tab sealant may be applied to at least aportion of the lower frame material 600 in order to help adhere thecurrent collector tabs 506, 508 to the lower frame material 600. A lowerouter packaging layer material 612, supplied from a suitable roller anddesirably including a low temperature heat sealant and moisture barrier,is then applied to the lower frame material 600. The battery cell 508 ofFIG. 5 is then placed into an opening 604 in the lower frame material600 and onto the lower outer packaging layer 612. The lower outerpackaging layer 612 may be heated (e.g., at 90° C.) prior to placing thebattery cell 508 thereon in order to promote adhesion. An upper framematerial 614 for the battery may be made in a manner similar to thatused for making the lower frame material 600 where a upper framematerial 614 is rolled out from a suitable roller and openings 616 arecreated in the upper frame material 614. A strip of z-axisanisotropically electrically conductive adhesive tape 618 placed abovean opening 616 in the upper frame material 614. The upper frame material614 is then placed over the battery cell 508 such that the electricallyconductive adhesive tape 618 is positioned over the anode and currentcollector tabs 506, 608. An upper outer packaging layer 620, desirablyhaving a low temperature heat sealant and moisture barrier layer, whichmay be of the same composition as the lower outer packaging material612, is then rolled out from a suitable roller and applied over thebattery cell 508. Optionally, a binder material may be included on theexterior surfaces of the upper and lower outer packaging layers 620, 612in order to facilitate the insertion of the resulting battery into adevice such as a smart card.

Two additional preferred embodiments: A) a single frame embodiment; andB) a frameless embodiment, are now described in reference to FIGS. 7-10.Optionally, an external frame can be used in the “frameless” embodiment(FIG. 10). These embodiments can improve the stability of the battery tolong term moisture ingress, as the number of seal layers can be reduced.This is particularly significant for lithium metal batteries becausemoisture can be very detrimental to lithium metal.

FIG. 7 illustrates an exploded view of elements in a battery having asingle frame design. In this embodiment, a one piece frame, 700, is usedrather than a two piece frame as shown in FIG. 1. A lower packagingmaterial 708 having substantially the same shape and perimeterdimensions as the one piece frame 700 may be disposed below and attachedto the frame 700. In the depicted embodiment, the outer edge 715 of thelower packaging material 708 and the outer edge 703 of the frame 700 aresubstantially flush with each other. The frame 700 is disposed below thebattery cell 706 and has an outer edge 703 that generally extends beyondthe periphery of the battery cell 706. Two current collector tabs 701,702 having distal ends 711, 713, extend from the periphery of thebattery cell 706. The length and width dimensions of the battery cell706 are not as long as those of the frame and lower packaging material.Hence, there is a gap 705 defined between the periphery of the batterycell and the outer edge of the frame. This gap may be about 3 mm wide,for example. The current collector tabs 701, 702 extend over this gap705 so that the distal ends 711, 713 of the tabs are substantially flushwith the outer edges of the frame 703 and lower packaging material 715.Thus, the current collector tabs 701, 702 rest on the top of and aresupported by the frame 700. FIG. 7 also illustrates a strip ofelectrically conductive tape 704, which can be an anisotropic conductivetape, disposed over the current collector tabs 701, 702. Theelectrically conductive tape 704 is shown here with a release liner 707partially peeled away. Hence, the current collector tabs 701, 702 aresandwiched between the conductive tape 704 and the frame 700 and, asshown in this embodiment, their distal ends 711, 713 are substantiallyflush with the outer edge of the conductive tape 717 and the outer edgeof the frame 703. Finally, an upper packaging material 710 is designedto cover the assembled battery cell 706, but is not as large as thelower packaging material 708. Rather, the outer edge 712 of the upperpackaging material 710 can be substantially flush with the inner edge714 of the strip of conductive tape 704, or a small gap (not shown) canbe engineered between the outer edge of the upper packaging material andthe inner edge of the conductive tape. One skilled in the art candetermine the best spatial relationship between the strip of adhesivetape and the upper packaging material and whether a small gap should beused. Contact between the upper packaging material and the top of theadhesive tape can result in shorting. Upon assembly, the top surface ofthe structure comprises the upper packaging material and conductivetape. In other words, the total area of the upper surface of thepackaged battery, which is equal to, or substantially equal to, the areaof the lower surface of the lower packaging material 708 isapproximately the sum of the area of the upper surface of the upperpackaging material 710 and the area of the upper surface of the adhesivetape 704. One advantage of this design is that, because a single pieceframe is used, only two seals are present, wherein (i) one seal joinsthe frame 700 with the upper packaging material 710 and (ii) the otherseal joins the frame 700 with the lower packaging material 708.

Upon assembly of the exploded elements in FIG. 7, the structure lookssubstantially like the structure in FIGS. 2 a and 2 b. In addition,packaging materials and frame materials which can be used in FIG. 7 arealso illustrated in FIGS. 3 and 4.

FIG. 8 illustrates an exploded view of an embodiment of a battery havinga frameless design, or at least absence of an internal frame, which canbe called a pouch cell, a bagged cell, or a sachet cell embodiment. Inthis design, no frame is present between the packaging materials.Rather, an assembled battery cell 801 with two current collector tabs806, 807, having distal ends 811, 813, extending outwardly from itsperiphery is disposed above a lower packaging material 800 and below anupper packaging material 808 without an internal frame. As noted below,an external frame can be provided (see FIG. 10). Here, the length andwidth dimensions of the lower packaging material 800 are longer thanthose of the assembled battery cell 801. Hence, there is a gap 805defined between the periphery of the battery cell and the outer edge ofthe lower packaging material 800. This gap may be about 3 mm wide, forexample. The current collector tabs 806, 807 which extend outwardly fromthe periphery of battery cell 806 extend over this gap 805 so that thedistal ends 811, 813 of the tabs are substantially flush with the outeredge 803 of the lower packaging material 800. Thus, the currentcollector tabs 806, 807 rest on the top of and are supported by thelower packaging material 800. FIG. 8 also illustrates a strip ofconductive tape 809, which can be an anisotropic conductive tape,disposed over the current collector tabs 806, 807. The conductive tapeis shown here with a release liner 804 partially peeled away. FIG. 8also shows the upper packaging material, 808. This upper packagingmaterial 808 can be substantially the same as the upper packagingmaterial 710 in FIG. 7. Also, the outer edge 815 of the upper packagingmaterial 808 may be substantially flush with the inner edge 817 of thestrip of conductive tape 809, or a small gap (not shown) can beengineered between the outer edge 815 of the upper packaging material808 and the inner edge 817 of the strip of conductive tape 809.

FIGS. 9 a and 9 b illustrate perspective views of the exploded structurein FIG. 8 in the assembled state. In these figures, the upper packagingmaterial 808 is shown with a raised middle portion 819 due to theunderlying battery cell 801. Upon assembly, the raised portion 819 maybe formed as the underlying battery cell 801 is pressed against theupper packaging material 808.

FIGS. 10 a and 10 b illustrate a preferred embodiment which can improveupon the frameless embodiment shown in FIGS. 8 and 9. In FIG. 10 a, anexternal frame, 1000, is used to help provide a battery having asubstantially uniform cross-sectional height. In this embodiment, theheight of the external frame 1000 is substantially the same as theheight of the raised middle portion 819 of the battery. As shown inFIGS. 10 a and 10 b, the external frame 1000 is disposed over the upperpackaging material 808 and is adapted to seat around the raised middleportion 819 of the battery. This external frame compensates for theraised portion and provides a more uniform cross-sectional height. Amore uniform cross-sectional height provides better assembly and bettercosmetic appeal in larger structures such as smart cards.

Although four sided seals can be carried out in these embodiments, threesided seals can also be carried out. For example, a single piece ofpackaging material can be folded over to provide upper and lowerpackaging materials from a single continuous piece of material. The foldcan be on the side of the battery cell opposite the side from which thecurrent collector tabs extend.

Although the battery constructions and packaging designs provided hereinmay be adapted for use with a variety of battery types, they areparticularly well-adapted as designs for flat packaged batteries, suchas thin polymer electrolyte batteries as described above in U.S. Pat.Nos. 5,888,672 and 6,451,480 to Gustafson et al. and in U.S. patentapplication Ser. Nos. 10/437,778; 10/437,559; and 10/437,546, filed May13, 2003 to Wensley et al. Briefly, these batteries can include polymermatrix electrolytes based on polyimides. More specifically, thesebatteries can include electrolytes composed of a polyimide, a lithiumsalt and at least one solvent. The lithium salt is desirably present ina concentration of at least 0.5 moles of lithium per mole of imide ringand the polymer electrolyte is desirably substantially optically clear.Other batteries that may benefit from the tab and packagingconstructions provided herein include those described in U.S.Provisional Patent Application No. 60/545,179. These batteries caninclude anodes composed of lithium powder and a polymer binder.

The present batteries are well suited for use inside smart cards, smartlabels, RFID tags, medical devices, and other small devices whichrequire lamination processing (e.g., high temperature/high pressurelamination or low temperature/reduced pressure lamination) and whichbenefit from an on board power supply. In some applications, use at lowtemperatures can be needed which would result in selection of materialsfor use of low temperature lamination or cold lamination (e.g., hightemperature materials may not be needed). This is particularly true forbatteries having regular perimeters (e.g., rectangular or square) whichcan be laminated into small, relatively flat devices without creatingsinks, pockets or other surface defects. The various components of thebattery may be selected (e.g., as described in U.S. patent applicationSer. Nos. 10/437,778; 10/437,559; and 10/437,546, filed May 13, 2003 toWensley et al.) to be able to withstand standard hot laminationprocesses used in the smart card industry. For example, in someinstances, the batteries may be designed to withstand temperatures of125 to 140° C. and pressures of 200 to 250 psi for dwell times of 5 to15 minutes.

The term smart card may be used to refer to any of a variety ofelectronically readable cards. These cards, which are generally smallflexible cards, e.g., plastic cards about the size of a credit card,typically include a microprocessing unit, a memory and an interface fortransmitting and receiving data from an external source. A typical smartcard includes a processor coupled to an electrically erasableprogrammable read-only memory (EEPROM), read only memory (ROM) and/orrandom access memory (RAM).

These components are fabricated onto a single integrated chip whichfurther includes a microprocessor for executing instructions and storingdata in the memory. Such smart cards further include an input/output(I/O) signal interface for exchanging I/O signals between the smart cardand an external device, such as a card reader. U.S. provisional patentapplication 60/570,097 filed May 12, 2004 (see also, Ser. No. 11/127,299filed May 12, 2005) further describes smart cards and charging designswhich can be used in combination with the present embodiments andadapted as needed to use with the present embodiments, the entiredisclosure being incorporated by references.

Smart labels (also known as radiofrequency identification (RFID) tags)refer to electrically powered labels that may be used to track a vastrange of products. Smart labels typically include microprocessing unit,an antenna and an encapsulating material and/or support. The label maybe powered by electric fields generated by a reader and communicate withthe reader through its antenna.

Medical devices can be adapted to incorporate the embodiments of theinvention described herein. For example, sensors can be fabricated tomeasure the temperature of a product such as blood which is temperaturesensitive, and the sensor powered with batteries as described herein.

The electronic device can comprise the battery as described herein andan electronic circuit. An electrical connection can be establishedbetween the at least one current collector tab and the electroniccircuit without a weld or solder. In preferred embodiments, the devicecan be a smart card, a smart label, an electronically readable card, anRFID tag, an electrically powered label, a medical device, a sensor, atemperature measurement device, or a wearable medical device.

The invention has been described with reference to various specific andillustrative embodiments. However, it should be understood that manyvariations and modifications may be made while remaining within thespirit and scope of the following claims.

1-8. (canceled)
 9. A battery comprising: (a) a battery cell; (b) atleast one current collector tab having a distal end extending from thebattery cell; and (c) a lower packaging material disposed below thebattery cell and having an outer edge that extends beyond a periphery ofthe battery cell; wherein the lower packaging material supports the atleast one current collector tab.
 10. The battery of claim 9, wherein theouter edge of the lower packaging material is substantially flush withthe distal end of the at least one current collector tab.
 11. Thebattery of claim 9, wherein the outer edge of the lower packagingmaterial is not substantially flush with the distal end of the at leastone current collector, and the distal end of the current collectorextends beyond the outer edge of the lower packaging material.
 12. Thebattery of claim 9 further comprising an upper packaging materialdisposed above the battery cell wherein the upper and lower packagingmaterials provide a pouch for the battery cell.
 13. The battery of claim12 wherein the upper packaging material and the lower packaging materialare comprised of a single continuous piece of packaging material. 14.The battery of claim 12 wherein the upper packaging material has anouter edge that does not extend to the distal end of the at least onecurrent collector tab.
 15. The battery of claim 9, further comprising anelectrically conductive tape disposed over the at least one currentcollector tab.
 16. The battery of claim 15, wherein the electricallyconductive tape has an outer edge that is substantially flush with thedistal end of the at least one current collector tab and an inner edgethat is directed toward the outer edge of the upper packaging material.17. The battery of claim 16, wherein a gap is defined between the inneredge of the electrically conductive tape and the outer edge of the upperpackaging material.
 18. The battery of claim 15, wherein theelectrically conductive tape comprises a z-axis anisotropic electricallyconductive tape.
 19. The battery of claim 12, having a raised middleportion, the battery further comprising an external frame seated aroundthe raised middle portion.
 20. The battery of claim 19, wherein externalframe has a height that is substantially equal to height of the raisedmiddle portion.
 21. The battery of claim 9, wherein the battery is alithium metal battery, a lithium ion battery or a polymer electrolytebattery.
 22. The battery of claim 9, wherein the battery comprises anelectrolyte comprising polyimide, lithium salt, and solvent.
 23. Anelectronic device comprising the battery of claim 9 and an electroniccircuit.
 24. The device of claim 23 wherein an electrical connectionbetween the at least one current collector tab and the electroniccircuit is established without a weld or solder.
 25. The device of claim23, wherein the device is a smart card, a smart label, an electronicallyreadable card, an RFID tag, an electrically powered label, a medicaldevice, a sensor, a temperature measurement device, or a wearablemedical device. 26-43. (canceled)